About Sensor NetworkCharacteristics: Applications: Temporarily formed Military battlefield Nodes act as routers networks. Infrastructure-less Personal Area Networks Limited resources Disaster and rescue wireless medium operation
Attacks on Wireless NetworksPassive attacks Do not change the routing information Listen to get valuable informationActive attacks Use its energy to manipulate the routing information
Passive attackpassive attack "attempts to learn or make useof information from the system but does notaffect system resources"Traffic analysis each message is encrypted because it is not important whether thedata is readable(understandable) to the attacker. Here, the adversary attemptsto find patterns in the communication between two node, which might allow the adversary to derive certain assumptions based on these patterns.
Active AttackActive attacks include security threats in which an node triesto manipulate code or data while it is transmitted betweennodes. The most common examples of this kind of attack arealterations, in which an data is deleted or tampered with by an intruder .
Active AttacksModification: Malicious node can modify routing informationFabrication: Generating false routing messageImpersonation: Initiate attack by masquerading as another node
Existing Security SolutionsIntrusion prevention Encryption, authentication.Nodes are required to have pre-shared keys or digitalcertificates.Central trust authority or pre configuration is not practicalfor ad-hoc networks
Dynamic Source Routing (DSR) ProtocolOn demand protocol: route informationdiscovered only as needed.Source routing: entire path to destinationsupplied by source in packet header.Procedure: •Route discovery •Route maintenance •Routing
Route Discovery. Route Request: Source broadcasts Route Request message for specified destination Intermediate node adds itself to path in message and forwards message toward destination A A,B A,B,C A,B,C,D A B C D E
DSR Based ModelTrust Based RoutingTo compute the direct trust in a node. In doing so we measure theaccuracy and sincerity of the immediate neighboring nodes by monitoringtheir participation in the packet forwarding.As soon as it hears its immediate neighbour forwarding the packet, thenode checks the integrity of the packet by verifying it for requisitemodifications. If the integrity check passes, it confirms that the node has acted in abenevolent manner and so its direct trust counter is incremented. Similarly, ifthe integrity check fails or the forwarding node does not transmit the packet,itscorresponding direct trust measure is decremented.
Trust PropagationTo propagate trust information beyond a single hop, piggyback the direct trust value of nodes along with the ROUTE REQUEST packets.Before forwarding a ROUTE REQUEST packet, appends the direct trustvalue of the preceding node from which it had received the ROUTEREQUEST packet.When the ROUTE REQUEST packet is propagated, it also spreads the trustinformation of other nodes in the network.
Trust Propagation Tba, Tax Tax A B Tcx, Tcx TdcX C D Y Tex, Tfe Tex E F
References1.TRUST-BASED ROUTING FOR AD-HOC WIRELESS NETWORKS , Asad Amir Pirzada., AmitavaDatta, Chris McDonald School of Computer Science & Software Engineering, The University ofWestern Australia Crawley, WA 6009, Australia2. An Intrusion Detection System for Wireless Sensor NetworksIlker Onat Ali Miri School of InformationTechnology and Engineering University of Ottawa, Canadae-mail: email@example.com, firstname.lastname@example.org. Intrusion Detection Techniques for Mobile Wireless Networks ,Yongguang Zhang ,HRL LaboratoriesLLC, Malibu, California Wenke Lee,College of Computing, Georgia Institute of TechnologyE-mail: email@example.comYi-An Huang,College of Computing, Georgia Institute of TechnologyE-mail: firstname.lastname@example.org